Building panels including a front plate, a rear plate and a core structure adhesively bonded to and sandwiched between the plates are known in the art. Such building panels may be found, for example, in the interior of buildings on walls and ceilings, or on the walls and ceilings of underground railway stations. The panels may serve to enhance the aesthetic, insulating and/or acoustic properties of the building. Depending on the panel's function, the front and/or rear plate may be provided with apertures. The core structure may be formed from honeycomb material and/or a foamed material, such as rock wool or the like.
The front plate and the rear plate each have two main surfaces, namely an interior surface which is bonded to the core structure and an exterior surface. One or each interior surface may be provided with one or more layers of nonwoven fabric. The exterior surface of the rear plate is intended to face a wall or ceiling and hence, when the panel is installed on a wall or ceiling, is not visible to people inside the building. However, the exterior surface of the front plate faces outwardly and is visible to people inside the building as they view the wall or ceiling. It is therefore desirable that the exterior surface of the front plate is aesthetically appealing.
Adhesively bonding the individual elements of the building panel together allows a panel to be rapidly and inexpensively assembled, and provides a building panel having an aesthetically acceptable visible front surface, free from bolts, rivets or the like.
However, when adhesively bonded building panels are subjected to extremely hot environments, such as, for example, during a fire in the building or underground railway station in which the panels are installed, the heat may cause the adhesive to melt, incinerate or otherwise disintegrate so as to loose its adhesive properties, resulting in the constituent parts of the panel separating. Where the building panels are located on the ceiling or high up on a wall, these constituent parts of the panel may fall onto firefighters or people trying to evacuate the building, causing injury. The present invention addresses this problem.